Scientists estimate that horn flies (Haematobia irritans) cost U.S. cattle producers at least $876 million each year. Together with fire ants and nuisance flies, they have a tremendously negative impact on the profits of farmers and ranchers in every industry.
Infestation occurs rapidly with 1000-4000 flies per animal in an untreated herd. In general, horn flies congregate on the back and shoulders of cattle and tend to rest quietly on the host. Horn flies rarely leave their host, except to lay eggs, change host animals, or remain outdoors when the host moves indoors.
Because they are a nuisance to the cattle, horn flies interrupt grazing patterns. The cattle tend to waste energy and even go off their feed. Due to horn fly infestations, calves are lighter at weaning by about 10-25 pounds. In addition, a 14% weight loss over a 120 day fly period can amount to 26 lbs. per head. In the summer season, horn flies can cause a loss of about 15-50 lbs. per head. At $0.90 per lb., a 30 lb. weight loss equals a $27.00 loss per head. Moreover, cows can go out of condition during breeding.
In addition, flies such as stable flies (Stomoxys calcitrans), house flies (Musca domestica), and face flies (Musca autumnalis) have a tremendously negative impact on animal health and economics. Stable flies are blood and flesh eaters with a strong painful bite that tend to reproduce in drier manure and straw combination environments. Their bite is so irritating that animals such as cattle do not feed, thereby causing a significant loss in their weight gain and a loss in profits of over $1 billion each year. House flies typically breed in manure, rotting material, or other moist places. Although house flies do not feed directly on animals, they annoy workers and reduce worker efficiency. Since house flies associate with manure and tend to enter homes, they are an efficient vector of disease and cause public health concerns. In fact, house flies are capable of transmitting numerous pathogens such as E. coli, Salmonella, and dysentery. Face flies are true manure breeders and cause pink eye and reduced weight gain in animals infested with them. The cost of face fly infestations, which include treating pink eye with antibiotics, amounts to over $150 million each year.
U.S. Pat. No. 3,929,453 discloses composites of lignin and biological active materials. The biologically active agent is either entrapped by the lignin macromolecular matrix or held by physical-chemical forces of van der Waal's, hydrogen bonding or ion association types. The active agent is slowly released on application either by diffusion through the lignin solid, or through degradation or dissolution of the lignin.
In view of the foregoing, there is a need in the art for more effective pesticide formulations that are economical and have low side-effects. There is also a need in the art for methods to control and treat insect infestations on livestock (e.g., horn fly, stable fly, house fly, or face fly infestations on cattle) and pets using such pesticide formulations. The present invention satisfies these and other needs.